5-oxo-1,4,2-dioxazines and preparation from alpha-amidooxy acids



United States Patent 3,420,824 -0X0-1,4,2-DIOXAZINES AND PREPARATIONFROM a-AMIDOOXY ACIDS Linus M. Ellis, Wilmington, Del., assignor to E.I. du

Pont de Nemours and Company, Wilmington, Del., a corporation of DelawareNo Drawing. Filed July 26, 1966, Ser. N 0. 567,818 US. Cl. 260-244 8Claims Int. Cl. C07d 87/00; A0111 9/20 ABSTRACT OF THE DISCLOSURE5-oxo-l,4,2-dioxazines, which are prepared by dehydrating2-amidooxycarboxylic acids in the presence of anhydrides or halides oforganic acids, acid halides of sulfur, phosphorus or silicon, or ketene,are useful as plant growth retardants.

This invention relates to, and has as its principal objects provisionof, new heterocyclic compounds which contain nuclear nitrogen bondeddirectly to nuclear oxygen and the preparation of the same. Thesecompounds are anhydro-a-amidooxy acids resulting from the removal ofwater from a-amidooxy carboxylic acids. Certain open-chain derivativesof the heterocyclic acids also form part of the invention.

The principal compounds of the invention can be assigned the formula Rand R alike or different, are hydrogen, aliphatic hydrocarbon of up to18 carbons in which any unsaturation is ethylenic and such aliphatichydrocarbon substituted with up to 2 halogens of atomic number 9-35,aromatic hydrocarbon of up to carbons and such aromatic hydrocarbonsubstituted with up to 2 halogens of atomic number 9-35 or with up to 2lower alkoxy radicals, or nitrogen heterocycles of 1 nitrogen and up to6 carbons; and

R is hydrogen, 1-4 carbon alkyl, or aromatic hydrocarbon of up to 7carbons.

These compounds are obtained by a liquid phase dehydration of oc(0l'2)-amidooxy acids for which may be written the general equation:

The dehydration is accomplished by reaction with an organic acidanhydride or halide, e.g., those of organic acids having up to 7carbons, inorganic acid halides such as those of sulfur, phosphorus, andsilicon, or ketene, in the liquid phase at a temperature in the range of0-100 C.

The dehydrating reaction probably proceeds through intermediateformation of a mixed anhydride or acid halide followed by elimination ofacid or hydrogen halide. As illustrated by the use of acetic anhydride(see Example 1) the reaction can be postulated as proceeding first via3,420,824 Patented Jan. 7, 1969 "ice the formation of a mixed anhydridefollowed by ring closure with elimination of acetic acid.

When thionyl chloride is used (see Example 2), the reaction probablyproceeds with intermediate formation of the acid chloride.

On the basis of the above reaction schemes, the reagents considereduseful in making anhydro-amidooxy acids from the amidooxy acids arethose that can cause intermediate formation of anhydrides or of acidhalides. Thionyl chloride is the reagent of choice because of thereadiness with which by-products (hydrogen chloride and sulfur dioxide)and any excess reagent are removed. Other reagents that can be usedinclude (1) other acid anhydrides, for example, propionic anhydride,butyric anhydride, benzoic anhydride, chloracetic anhydride, andtrifluoroacetic anhyride; (2) acid halides of organic acids, forexample, acetyl chloride, butyryl chloride, benzoyl chloride, methylchloroformate, chloroacetyl chloride, acetyl bromide and oxalylchloride; (3) ketenes, particularly ketene itself; and (4) inorganicacid halides such as phosphorus pentaor trichloride, phosphorusoxychloride, phosphorus tribromide, and silicon tetrachloride.

Solvents and/or acid acceptors may be present during the reaction. Inthe case when phosphorus halides are employed, it is generally desiredto have pyridine present, and when thionyl chloride is used, thepresence of dimethyl formamide facilitates the reaction.

Useful solvents or inert diluents that may be present includetetrahydrofuran, pyridine, dialkyl amides such as dimethyl formamide,etc. The reaction is effected under anhydrous conditions since thedehydrating agents react rapidly with Water.

The reagent is employed preferably in an amount at least equivalent on amolar basis to the acid being dehydrated. Excess amounts are generallypresent since many of the reagents can function as solvents and also berecovered or removed upon completion of the reaction.

It should be noted that a four-membered heterocyclic ring could betheoretically formed by the dehydration of this invention, i.e.,

As pointed out in Example 1, below, it is considered that thesix-membered ring is much more likely to be produced, and the compoundsare named accordingly. The compounds, moreover, shows a single carbonylband in the infrared spectrum at about 1800-1825 CH1. 1.

In any event, the anhydroamidooxy acid heterocyclic product formed isgenerally a solid or high-boiling liquid with limited stability towater. It should be protected against moisture if storage for anyconsiderable time is intended. The solid products can be purified byrecrystallization from inert organic solvents.

The dioxazine--(6H)-ones of this invention have useful plantgrow-th-regulant properties as noted below. They are also useful for thepreparation of the corresponding amides and esters by direct reactionwith the appropriate amines or alcohols. Although some esters are old inthe art, both they and the amides, which are new compounds, also haveplant growth-regulant properties.

The general formula for the novel amides, which form one aspect of theinvention, may be written as:

where R R and R are as previously defined and R and R alike ordififerent, are hydrogen, alky-l, aryl, lower alkoxy-alkyl, alkoxyaryl,carbalkoxyaryl, carbalkoxyalkyl, cyanoalkyl, cycloalkyl, and nitrogenheterocycles with up to 2 nitrogens and 5-6 ring members, and wherein Rand R together have up to generally about 12 carbons. Preferred amidesare those of Formula II wherein R is aromatic, R is hydrogen, R ishydrogen or lower alkyl, R is hydrogen or lower alkyl and R ishydrocarbon.

The preparation of the amides can be illustrated by the followingequation:

where the Rs are as previously defined. The general preparation can becarried out as follows: An amine is added to a solution containing anequivalent molar amount of a 3-aryl-1,4,2-dioxazine-5-(6H)-one inanhydrous ether or tetrahydrofuran present in an amount of -25 timesthat of the dioxazine on a weight basis. The solution is stirred atreflux for about minutes. Evaporation of solvent leaves a residue whichcan usually be recrystallized from commercial hexane to giveN-substituted 2-(arylamidooxy)alkanoamide.

The following examples in which the parts given are by weight furtherillustrate the preparation and properties of the new compounds of thisinvention. Examples 1-5 disclose compounds of Formula I, above, andExamples 6-23, Formula II.

Example 1.6-methyl-3-phenyl-1,4,2-

dioxazine-S- 6H) -one A. A preparation of 2-(-benzamidooxy)propionicacid, was carried out as follows:

A mixture of 274 parts of benzohydroxamic acid, 950 parts of absolutealcohol and a solution of parts of sodium hydroxide in 800 parts ofdistilled water was placed in a reaction vessel equipped with a stirrerand packed in a bath containing about 15,000 parts of icewater mixture.When the mixture was thoroughly chilled, 306 parts of a-bromopropionicacid were added and the mixture was stirred in the bath for 16 hours.The bath was removed, and the mixture was stirred at reflux for 0.5hour. Alcohol was removed by distillation under water pump vacuum, andthe residue was diluted with 300 parts of distilled Water. Concentratedhydrochloric acid parts) was added and the acidified solution wasextracted with two portions of ethyl acetate totalling about 1350 parts.The extract was dried by filtration first through a bed of sodiumchloride and then through a bed of anhydrous magnesium sulfate.

The dried filtrates from two preparations made as described above werecombined, and most of the solvent was evaporated on a steam bath. Solidthat separated on cooling was collected on a filter, dried, andrecrystallized from ethyl acetate. The weight of2-(benzarnidooxy)propionic acid obtained was 544 parts (65% of theory),M.P. 129.5130.5 C.

B. Ten parts of 2-(benza-midooxy)propionic acid was dissolved in 88parts of te-trahydrofuran. Twenty parts of acetic anhydride and aboutone-tenth part of concentrated hydrochloric acid were added, and theresulting solution was allowed to stand 96 hours in a stoppered flask.The solution was then poured into several volumes of Water. An oilylayer separated, and solidified on standing. This solid was collected ona filter, washed with water, dried, and recrystallized from petroleumether. Four parts of solid with a melting point of 65.566.5 C. wasobtained. Analytical data corresponded to a compound resulting fromabstraction of a molecule of water from a molecule of2-(benzamidooxy)propionic acid.

Analysis.Calcd. for C H NO Z C, 62.77; H, 4.75; N, 7.33. Found: C,62.78, 62.83; H, 5.16, 5.17; N, 7.27.

C. Another preparation carried out by the above procedure using 20 partsof 2-(benzamidooxy)propionic acid and proportionate quantities of othermaterials gave as product 13 parts of 6-methyl3-phenyl-1,4,2-dioxazine-5- (6H)-one, (alternatively,6-methyl-3'-phenyl-5,6-dihydro- 1,4,2-dioxazin-5-one), M.P. 66-67 C. Asmall portion of this material thoroughly mixed with an equal quantityof the previous product also gave a melting point of 6667 C. Infraredspectra of the two products Were substantially indentical. The molecularweight of the latter product determined by the boiling point method inbenzene solution was 220 (theory is 191). These data show that the twoproducts were the same, and were not compounds with an empirical formularepresented by some multiple of C H NO The abstraction of Water from2-(benzamidooxy)propionic acid could lead to the following structures:

III.

The new compounds of this invention have been assigned the dioxazinestructure (I) because of the greater ease of formation of the 6-memberedring, and in view of the spectral properties. The infrared spectrum hasa strong carbonyl band at 1800 cmf with weaker bands at 1575 cm." and1610 cm. attributed to aromatic -'C=C- and/or -C=N. On the basis ofliterature reports, exocyclic carbonyl as in structure IV would haveabsorption at about 1650 cmf Example 2 A mixture of 110 parts ofZ-(benzamidooxy)propionic acid and 165 parts of thionyl chloride wasstirred 2 /2 hours at reflux. Hydrogen chloride ceased to evolve. Excessthionyl chloride was distilled from the reaction mixture by heating on asteam bath under water pump vacuum. A test portion of the residue wasrecrystallized from petroleum ether. This melted at 6667 C. and gave aninfrared spectrum identical with that of the material from Example 1,showing identity with that material.

The balance of the crude product was recrystallized from commercialhexane to yield 86 parts (86% of theory) of6-methyl-3-phenyl-1,4,2-dioxazine-5-(6H)-one with a melting point, afterdrying in vacuum to remove solvent, of 66-67 C.

Example 3 The method described in Example 2 was used to prepare6-methyl-3-phenyl-1,4,2-dioxazine-5-(6H)-one from 100 parts of2-(benzamidooxy)propionic acid and 150 parts of thionyl chloride. Theproduct weighed 66 parts and melted at 66.367.3 C. The mass spectrum ofthis compound showed a parent ion corresponding to a molecular weight of191.

Example 4.3-phenyl-1,4,2-dioxazine-5-(6H)-one A. 2-(benzamidooxy)aceticacid was prepared as follows:

A solution of 160 parts of sodium hydroxide in 800 parts of distilledwater was added with stirring to a mixture of 274 parts ofbenzohydroxamic acid in 950 parts of absolute alcohol. The mixture wasthoroughly chilled in an ice .bath. Two hundred and seventy eight partsof bromoacetic acid was added, and the reaction mixture was stirred 16hours in an ice bath. The reaction mixture was then heated at reflux for0.5 hours, after which alcohol was removed under water pump vacuum, withheating on a steam bath. The residue was made acid by addition of 245parts of cone. hyrochloric acid and extracted with 1600 parts of ethylacetate in two portions. The extract was dried by filtration, firstthrough a bed of sodium chloride and then through a bed of anhydrousmagnesium sulfate. Most of the solvent was evaporated on a steam bath toleave a residue that formed a mushy solid on cooling. This was filteredto remove liquid, and solid was recrystallized from ethyl acetate. The2-(benzamidooxy)acetic acid thus obtained (233 parts) melted at 142- 143C. McHale et al., J. Chem. Soc. 1964, 225, give 144- 145 C. as themelting point of 2-(benzamidooxy)acetic acid made by a closely analogousprocedure.

B. A mixture of 50 parts of 2-(benzarnidooxy)acetic acid and 125 partsof thionyl chloride was stirred under a very gentle reflux. After 0.75hour the evolution of hydrogen chloride appeared to diminish strongly,and after a brief period to resume strongly. At the same time thesolution became red in color. Heating at reflux was discontinued at thispoint, and readily volatile material was removed by gentle heating underwater pump vacuum. The residue was vacuum distilled to obtain a majorportion with a tan to amber color and a boiling point of 107 C. at 0.9mm. to 110 C. at 1.0 mm. The material solidified on standing, M.P. 25.5-27 C.

Analysis.Calcd. for C H NO C, 61.02; H, 3.98; N, 7.91. Found: C, 61.27;H, 4.14; N, 7.91.

This compound, 3-phenyl-1,4,2-dioxazine-5-(6H)-one or3-phenyl-5,6-dihydro-1,4,2-dioxazin-5-one, resembled the 6-methylderivative in having a single carbonyl band at about 1820 cm.- withmoderate to strong bands at 1490, 1560 and 1600 cm.- attributed tomonosubstituted phenyl groups and to the -C=N group. The mass spectrumof the compound showed a parent ion corresponding to a molecular weightof 178.

Example 5 .6-ethyl-3-phenyl- 1 ,4,2-dioxazine-5- 6H one crystallizationof the crude product from ethyl acetate there was obtained 127.5 partsof 2-(benzamidooxy)butyric acid with a melting point of 132.5-1335" C.

B. A mixture of 32 parts of 2-(benzamidooxy)butyric acid and 92 parts ofthionyl chloride was stirred at reflux for 30 minutes, when evolution ofhydrogen chloride had largely ceased. Excess thionyl chloride wasremoved by heating on a steam bath under aspirator vacuum. The residuewas distilled from a small Claisen flask to yield mainly 23 parts of6-ethyl-3-phenyl-1,4,2-dioxazine-5- (6H)-one, (alternatively,6-ethyl-3-phenyl-5,6-dihydro- 1,4,2-dioxazin-5-one), with a boilingpoint of 99 C. at 0.05 mm.

Analysis.-Calcd. for C H NO C, 64.38; H, 5.40; N, 6.83. Found: C, 64.58;H, 5.41; N, 7.06.

The infrared spectrum of this compound showed the same strong carboxylabsorption at about 1825 cm. as the other dioxazine derivatives.

Table I, which follows, illustrates additional compounds of the generalFormula I that are obtainable by the procedures given in the aboveexamples:

TABLE I [Formula 1] Compound R R R Acid used in dehydration 1.6-rnethyl-3-undecyl-1,4,2- Undecyl Hydrogen... \iethyl2-(lauramidooxy)propidioxazinc-5-(6H)-one. onic acid.

2. 3-(2-mcthylpropyl)-6-phenyl- 2-methylpropyl .do... Phenyl..........2-(isovaleramidooxy)- 1,4,2-dixazine-5-(GED-one. phenylacetic acid.

3. 6,6-dimethyl-3-pl1enyl-1,4,2- Phcnyl Methyl Methyl2-(benzamidooxy)isodioxazine-fi-one. butyric acid.

4. 3-phenyl-6-decyl-l,4,2- .....do... Hydrogen... Decyl2-(benzamidooxy)lauric dioxazinc-S-(GED-one. acid.

5. 3-methyl-6-pi1cnyl-1,4,2- Methyl" ...do....-.. Phcnyl..........2-(acetamidooxy)phenyldioxazine-(6H)-one. acetic acid.

6. G-(p-chIQmphenyD-Sphenyl Phenyl ..do p-Chlorophenyl.2-(benzamidooxy)-p- 1,4,2-dioxazine-5-(SID-one. chlorophenglacetic aci7. 6-(1-1ncthylpropyD-3-(pp-Chlorophcnyl ..do.... l-nicthylpropyl..Z-(p-chlorobcnzamidochlorophenyl)-1,4,2 dioxazineoxy)-3-methylvalerio5-(6H)-one. ac

8. 6-n1ethyl-3-(3-pyridyl)-l,4,2- 3-pyridyl .do.. Methyl2-(nicotinamidooxy)- dioxazine-5-(6H)-one. propionic acid.

9. (rmethyl-3-cyclopcntyl-1,4,2- Cyc1openty1..-. .d0.. do.fZ-(cyclopentanecarbondioxazine-5-(6H)-one. amidooxy)propouic 10.G-cyclohexyl-3-phcnyl-l,4,2- Phenyl ..do Cyclohexyl.2-(benzamidooxy)cyclodioxazinc-5-(6H)-one. hexylacetic acid.

11. 3-berizyi-6-methyl-l,4,2- Benzyl ..do Methyl 2-(phcnylacetamidooxy)-dioxazinc-5-(6H)-one. propionic acid.

12. 3-hexyl-6-methyl-1,4,2- Hexyl ..do ..do 2-(enanthamidooxy)-dioxazine-5-(6H)-one. pro pionic acid.

13. 3-(4-methoxyphenyD-6- 4-methoxyphenyl ..do a-N apl1thyl.....2-(p-anisamidooxy)-a- (a-naphthyl)-1,4,2-dioxazinenaphthylacetic acid.5-(6H)-one.

14. 3-(n1-to1yl)-6-(3-phcnylm-Tolyl ..do. 3-pheny1propyL.2-(1n-toluamidooxy)-5- propyl) -1-4,2-dioxazine-5- phenylvaleric acid.(fii-D-onc.

l5. fi-methyl-l,4,2-dioxazine-5- Hydrogen ..do Methyl 2-(tormamidooxy)-H -one. propionic acid.

16. 3-phenyl-6-(3-pyridyl)-1,4,2- Phenyl. ..do 3-pyridyl2-(benzamidooxy)-3- dioxazine-5-(6H)-one. pyridyl-acetic acid.

17. 3-vinyl-6-Inethy-1,4,2- Vinyl ..dO Methyl 2-(acrylamidooxy)-dioxazine-5-(6H)-one. propionic acid.

18. 3,6,6-triphenyl-l,4,2- Phenyl Phenyl.... Phenyl2-(benzamidooxy)-2,2-

dioxazine-5-(6ID-one.

diphenylacetic acid.

Of the preceding compounds, those particularly preferred have at leastone hydrogen on nuclear carbon (R Nine and six tenths parts ofn-dodecylarnine was added and have hydrocarbon radicals on themaintaining R and 35 to a soution of parts of 6 methy1 3 pheny1 142 diOXR positions with a total of up to 12 carbons. Preferably, R is aryl andR is lower (l4 carbon) alkyl.

Example 6.-N-dodecyl-2 (benzarnidooxy)propionamide azine-5-(6H)-one in284 parts of anhydrous ether. The solution was stirred at reflux forminutes. Evaporation of ether left 19.5 parts of residue. This wasrecrystallized from commercial hexane to yield 17.5 parts of N-dodecyl-2-(benzamidooxy)propionamide. After drying overnight N CHCHQ OHHHNH?under vacuum to remove any residual solvent, this product ll o CaH5C 0 0melted at C.

Analysis.Calcd. for C H N O C, 70.17; H, 9.10;

N, 7.44. Found: c, 70.39; H, 9.52; N, 7.37. H H Table II, which follows,shows products of Formula II Gallic-N110C(CHa)HCNHC11Hw obtained whenthe above method of Example 6 is used. (Formula II: R CtH5; R =R =H; R=CHa; R =Cl2H25) TABLE II [Formula II] Dioxazine Percent Melting Examplederivative Amine used Product obtained R yield 1 point, 0.

use

Dodecylamine N-dodecyl(benazmidooxy)acetamidc..- Hydrogem. Dodecyl 8373-74 Methylamine...-.. N-methyl(benzamidooxy)-acetamide ..do-.....Methyl. 80 116. 5-118 Dimethylaminc-.. N,Iiadimethyl(benzamidooxy)aceta-Methyl .-do 80 122-123.5

In c. Isopropyiamine N-isopropyl(benzamidooxy)acetamide.- Hydrogen..Isopropyl 45 78-79 A 2-(benzamidooxy)-propionamide 0...... Hydrogen 36154-155 2-(benzamidooxy)-propionanilide ..do. Phenyl. 152-153N,N-dimethyl-2-(benzamidooxy)pro- Methyl"--. Methyl -91 pionamide.Methylamine N-rn8thyi-2-(benzamidooxy)-propiona- Hydrogen ..do 30 115.5-116 ml e. Diethylamine..... N,N-diethgl-2-(benzamidooxy)pro- EthylEthyl 72 127-128 pionami e. Methyl Z-amino- Methyl2-[2-benzamidooxy)-propiona- Hydrogen.. l-(carbomethoxy) 24 164-165oxy-propionate. midooxy1propionate. ethoxy. 2-aminopyrimi-N-(Z-pyrimidinyD-Z-(benzamidooxy)- ..-..do 2-pyrimidinyl.-.. 38 169-170dine. propionamide. 2-amino-4-methyl-N-(4-methyl-2-pyrimidinyl)-2-(benz- .--..do 2(4-methyl)- 33 148.5-149.5

pyrimidine. amidooxy)propionamide. pyrimidinyl. 19 II 2-amino-4,6-di-N-(4,ddimethyl-2-pyrimidinyl)-2- -...d0--...- 2(4,6-dimethyl)- 60127-129 giethylpyrimi (benzamidooxy)propionamide. pyrimidmyl.

me. 20. II-.. Ethyl 4-amino- N-(4-carbethoxyphenyl)-2-(benzamido--....4-carboethoxy- 57 153.6-154 benzoate. dooxy)propionate. phenyl. 21.-. IIN-ethyl-Z-cyano- N-ethyl-N-(2-cyanoethyl)-2-(benzami- Ethyl Z-cyanoethylLiquid ethylamine. dooxy)propionamide. 22.-. II HexylamineN-herfgi-Z-(benzamidooxy)-propion- Hydrogen. Hexyl 94 116. 7-117.5

am e. 23 III Ammonia 2(benzamidooxy)butyramide ....do Hydrogen 58170-171 1 Precent yield is based on dioxazine derivative used.

oxazin-eone, i.e.

Alcoholysis of the 2-(N-arylamidooxy) -acid amides in the presence ofhydrogen chloride leads to the hydrochlorides of the aminooxy acidamides. For example, hydrogen chloride was passed into a solution of 18g. of N- dodecyl-2-(benzamidooxy)propionamide in 100 ml. of methanol ata rate suflicient to heat the solution to reflux. The solution wasmaintained at reflux for 15 minutes by introduction of hydrogenchloride. The product was evaporated on a steam bath leaving a liquidresidue that solidified on cooling. This residue was recrystallized fromethyl acetate to obtain 11 g. of the hydrochloride of N-dodecyl-2-(aminooxy)propionamide melting at 106.2-108.2 C.

Analysis.-Calcd. for C H ClN O C, 58.32%; H, 10.77%; N, 9.07%. Found: C,58.99%; H, 10.43%; N, 8.96%.

A similar procedure was used to prepare the hydrochloride ofN-hexyl-Z-(aminooxy)propionamide from N-hexyl-2-(benzamidooxy)propionamide. After recrystallization from ethylacetate the product melted at 94-95 C.

Analysis.--Calcd. for C H ClN O C, 48.09%; H, 9.42%; N, 12.46%. Found:C, 48.37, 48.23%; H, 9.46, 9.04%; N, 12.36, 12.46%.

The new amidooxyamides prepared as described in Example 6 and furtherillustrated in Table II are active for biological growth control. Whenthe amides are derived from ammonia or lower amines (e.g., those up toabout 8 carbons), the compounds when applied post-emergence at a rate of2-5 lbs./ acre retard the growth of grasses, particularly Johnson grass,and produce hormone response and axillary stimulation.

Derivatives of higher amines, e.g., 2-(benzarnidooxy)-N-dodecylacetamide when used at a concentration of 10 *y/ml. controlStaphylococcus aureus. Furthermore, derivatives of the latter compoundobtained by alcoholysis, e.g., N-dodecyl-Z-(aminooxy)propionamidehydrochloride, also control the growth of such bacteria asStaphylococcus aureus, Streptococcus pyogenes and Bacillus subtilis inliquid media at 10 7/ ml.

The preparation of esters of the anhydro acids of this invention can beillustrated as follows:

Example 24.--Al1yl-2-(benazrnidooxy)propionate O N (IJHCHs CH2=CHCH2OHGaseous hydrogen chloride was passed for 10 seconds into a stirredsolution of parts of 6-methyl-3-phenyl- 1,4,2-dioxazine-5(6H)-one in 64parts of allyl alcohol. The solution was stirred at reflux for 1.5 hoursafter which excess allyl alcohol was removed by distillation under waterpump vacuum. The residue was distilled from a small Claisen flask toobtain 11 parts of allyl 2-(benzamidooxy)propionate as a viscous liquidwith a boiling point of 130-135 C. at 0.03-0.05 mm.

Analysis.-'Calcd. for C H NO C, 62.64; H, 6.07; N, 5.62. Found: C,62.20; H, 6.08; N, 5.01, 4.98.

Substitution of other alcohols for allyl alcohol gives correspondingesters. Suitable alcohols are amyl, isopropyl, ethyl or methyl alcohols.Similarly the specific dioxazine used can be replaced by otherdioxazines as described previously; see, for example, Table I.

Allyl Z-(benzamidooxy)propionate is an active postemergence herbicide atboth 16 and 2 lb./ acre. The effect at 2 lb./acre is principally one ofgrowth retardation, hormone action and axillary stimulation; and, ontobacco, inhibits the growth of suckers. 6-methyl-3-phenyl-1,4,2-dioxazine-5-(6H)-one is a strong growth retardant on grasses whenapplied preor post-emergence by spraying a solution at a rate equivalentto 16 lb./ acre. It is a fairly strong growth retardant at 2 lb./ acrein post-emergence 10 tests, and in test gave about 40% control oftobacco suckering, but with some burn.

Biologically active compositions of compounds of the present inventioncan be prepared by admixing at least one of the active compounds withpest-control adjuvants or modifiers to provide compositions in the formof dusts, Water-dispersible powders, high-strength concentrates, andsolutions or dispersions in inert organic liquids. They can be used witha carrier or diluent agent such as a finely divided solid, an organicliquid, a dispersing agent, an emulsifying agent, or any suitablecombination of these. The new dioxazines react with compounds containingactive hydrogen such as amino and hydroxyl-containing compounds and,upon contact with water, are hydrolyzed. However, at ordinarytemperatures the rate is relatively slow. For use in plant growthcontrol, it is preferred that they be formulated in nonaqueous systems,or used relatively soon after dilution or mixture with water.

The following specific formulations, in which percentages are by weight,are presented to illustrate the use of the new dioxazines of thisinvention:

EXAMPLE A A formulation is made up from the following ingredients:

Percent 3-phenyl-1,4,2-dioxazine-5-(6H)-one 10 Diatomaceous silica 30Micaceous talc 60 A formulation is made up from the followingingredients:

Percent 3-phenyl-1,4,2-dioxazine-5-(6H)-one 15 Sodium lauryl sulfate 60Synthetic fine silica 25 The above composition is prepared by blending,grinding, and reblending the components.

The above composition of 3-phenyl-1,4,2-dioXazine-5- (6H)-one is appliedin the spring at the rate of 25 pounds of active ingredient to an acreinfested with seedling Johnson grass and barnyardgrass. The treatmenteffectively controls these species.

EXAMPLE C Another formulation is made up from:

Percent B-phenyl-1,4,2-dioxazine-5-(6H)-one Dioctyl sodiumsulfosuccinate 2 Synthetic fine silica 8 The above composition is groundto pass a 50-mesh screen. It can be used directly or in furtherformulation.

EXAMPLE D Another formulation is made up from:

Percent 6-ethyl-3-phenyl-1,4,2-dioxazine-5-( 6H) -one 25 Alkylphenolpolyethylene oxide condensate 13 Xylene 62 The above emulsifiable oil isprepared by mixing the components with agitation until a homogeneoussolution results. The oil may be emulsified with water directly beforeuse or extended with additional oil for application.

Since obvious modifications and equivalents in the invention will beevident to those skilled in the chemical arts, I propose to be boundsolely by the appended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A compound of the formula 1 1x2 6(|3-R3 R C3 50:0

wherein R and R alike or different, are selected from the groupconsisting of hydrogen; aliphatic hydrocarbon of up to 18 carbons inwhich any unsaturation is ethylenic and such aliphatic hydrocarbonsubstituted with up to 2 halogens of atomic number 9- 35; aromatichydrocarbon of up to 10 carbons and such aromatic hydrocarbonsubstituted with up to 2 halogens of atomic number 935 or with up to 2lower-alkoxy radicals; and 3-pyridyl; and

R is selected from the group consisting of hydrogen; 1-4 carbon alkyl;and aromatic hydrocarbon of up to 7 carbons;

12 a Z-amidooxy acid of the formula ll l R -oNHo-0ooon R R and R beingas defined in claim 1,

by means of a member of the group consisting of: alkanoic acidanhydrides of up to 7 carbons; alkanoic acid chlorides of up to 7carbons; tri-fluoroacetic anhydride; chloracetic anhydride; chloroacetylchloride; oxalyl chloride; acid halides of sulfur, phosphorous andsilicon; and ketene.

6. The process of preparing the compound of claim 2 which comprisesdehydrating Z-(benzamidooxy) pro pionic acid in liquid phase and at atemperature in the range O-100 C. by means of a member of the groupconsisting of acetic anhydride and thionyl chloride.

7. The process of preparing the compound of claim 3 which comprisesdehydrating 2-(benzamidooxy)acetic acid in liquid phase and at atemperature in the range 0100 C. by means of thionyl chloride.

8. The process of preparing the compound of claim 4 Which comprisesdehydrating 2-(benzarnidooxy)butyric acid in liquid phase and at atemperature in the range 0100 C. by means of thionyl chloride.

U.S. Cl. X.R.

